Lesson at a Glance | He Tirohanga Whakamua
Ngā Whāinga Ako | Learning Intentions
Students will know
- The composition of Aotearoa New Zealand's electricity grid (~85% renewable: hydro, geothermal, wind) vs total energy footprint.
- Every renewable energy technology involves genuine trade-offs (e.g. hydro dams vs fish pathways, wind vs visual landscape, solar vs battery metals).
- How Māori trusts and iwi (e.g. Ngāti Tūwharetoa, Tuaropaki Trust) lead world-class geothermal energy stewardship.
Students will demonstrate
- By completing an Energy Input Audit for their chosen product area.
- By writing Design Journal Section 5: Energy Analysis with clear renewable power trade-off justifications.
Do Now | Tīmatanga Whakaaro (10 min)
Fact Check Prompt:
"Aotearoa generates ~85% of its electricity from renewable sources (hydro, geothermal, wind). So why does our transport and industrial sector still generate massive carbon emissions?"
Unpack: Electricity is only ~20% of NZ's total energy use! The remaining 80% comes from petrol/diesel for vehicles, process heat in dairy factories (burning coal/gas), and agricultural emissions. A technology product can run on renewable electricity but still have a huge fossil-fuel footprint in manufacturing or transport.
NZ Renewable Energy Trade-Off Matrix (15 min)
💧 Hydro (54% of generation)
Benefit: Reliable, dispatchable, low operational carbon.
Trade-off: Floods wetlands, disrupts longfin eel (tuna) migration, vulnerable to dry years.
🌋 Geothermal (20% of generation)
Benefit: Continuous 24/7 baseload power, independent of weather.
Trade-off: Minor CO₂/hydrogen sulfide gas emissions, requires reinjection technology to prevent aquifer depletion.
🌬️ Wind (9% of generation)
Benefit: High wind capacity factor in NZ, rapid deployment.
Trade-off: Intermittent (needs backup), visual/cultural landscape concerns, bird impact risks.
☀️ Solar (about 1% of generation)
Benefit: Decentralized, roof-mountable, drops peak summer grid loads.
Trade-off: Winter generation drops when NZ power demand peaks; panel manufacturing footprint.
🌿 Māori Geothermal Innovation: Tuaropaki Trust
The Tuaropaki Trust (near Mokai/Taupō) operates the Mokai Geothermal Power Station — an indigenous-owned enterprise that uses geothermal steam to generate 110 MW of clean electricity, power an automated commercial greenhouse (growing tomatoes without fossil fuels), and produce green hydrogen. This demonstrates kaitiakitanga as high-tech energy innovation.
Activity: Product Energy Audit (15 min)
Students evaluate the energy profile of their chosen product area across two phases:
- Manufacturing Energy: What energy sources are used to extract materials and manufacture your product? How could high-temperature processes (e.g. glass/metal smelting) transition to renewable heat?
- Use-Phase Energy: How much power does the device consume during daily use? Could it be powered by solar, kinetic energy, or ultra-low-power microchips?
📓 Design Journal — Section 5: Energy Analysis
Students open their Design Journal and write Section 5:
Section 5 Requirements:
1. Product Energy Audit: Identify the main energy inputs across the lifecycle of your product.
2. Renewable Transition Plan: Name ONE renewable energy source (solar, geothermal, hydro, bio-energy) that could power its production or use.
3. Honest Trade-off Analysis: State the realistic trade-off of this energy transition (e.g. higher initial cost, intermittency, or material availability).
Exit Analysis | Ka Mutu Hoki (5 min)
Exit Ticket Question:
"To make my product energy-sustainable, I would replace [Fossil energy input] with [Renewable source], acknowledging the trade-off of [Specific trade-off]."
Teacher Planning & Curriculum Alignment
NZ Curriculum Alignment (Technology — Phase 3 / Years 9–10):
- Technological Knowledge: Analyse how energy transformations power technological systems and evaluate the efficiency of renewable vs non-renewable energy inputs.
- Nature of Technology: Investigate how indigenous knowledge systems (mātauranga Māori) guide sustainable energy stewardship.
Vocabulary: Renewable energy mix, baseload power, intermittency, embodied carbon, geothermal reinjection, energy trade-offs.